Influence of sweet tasting solutions on opioid withdrawal.

The effect of the ingestion of palatable fluids on the suppression of opioid withdrawals in the opioid-dependent rats was studied. Physical dependence was induced by administration of morphine over a period of 6 days. Withdrawals were precipitated with naloxone (1 mg/kg, s.c.) 4 h after the last morphine injection on the 6th day. Test drugs (10-30% sucrose solution) were given orally for 2 h prior to naloxone-induced withdrawal in 14 h water deprived rats. Somatic signs of withdrawals were scored by using the global Gellert-Holtzman rating scale. Animals pretreated with low doses of sucrose solution (10-15%) did not produce any effect on the global withdrawal scale whereas a significant decrease on the global withdrawal scores was observed at higher doses of sucrose solution (20-30%) as compared to the controls. All the individual behavioral signs of withdrawals were significantly suppressed in a dose-related manner at higher doses of sucrose solutions whereas minimal suppression was observed for facial fasciculation/teeth chattering. These findings provide support that ingestion of high concentrations of sucrose solutions for shorter duration may activate the endogenous opioid system and appears to have an important role in modifying morphine withdrawals.